package com.ml.mall.utils;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import java.util.HashSet;
import java.util.Set;

/**
 * @description: 此类用于 Bean 拷贝 去除 null 拷贝
 * @author kyyang
 * @date 2021/6/1 21:49
 * @version 1.0
 */
public class SpringUtil implements ApplicationContextAware {

    /** 
     * 当前IOC 
     *  
     */  
    private static ApplicationContext applicationContext;  

    /** 
     * * 设置当前上下文环境，此方法由spring自动装配 
     *  
     */  
    @Override  
    public void setApplicationContext(ApplicationContext arg0)  
            throws BeansException {  
        applicationContext = arg0;  
    }  

    /** 
     * 从当前IOC获取bean 
     * 
     * @param id 
     * bean的id 
     * @return 
     *
     */  
    public static Object getObject(String id) {  
        Object object = null;  
        object = applicationContext.getBean(id);  
        return object;  
    } 
    
    public static String[] getNullPropertyNames (Object source) {
        final BeanWrapper src = new BeanWrapperImpl(source);
        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();

        Set<String> emptyNames = new HashSet<String>();
        for(java.beans.PropertyDescriptor pd : pds) {
            Object srcValue = src.getPropertyValue(pd.getName());
            if (srcValue == null) emptyNames.add(pd.getName());
        }
        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }

    public static void copyPropertiesIgnoreNull(Object src, Object target){
        BeanUtils.copyProperties(src, target, getNullPropertyNames(src));
    }

}